/**
 * LengthOfString
 * 计算字符串字面量类型的长度 => 数组长度
 */
 type LengthOfString<T, A extends any[] = []> = T extends `${infer L}${infer R}` ? LengthOfString<R, [...A, L]> : A["length"]
 type A = LengthOfString<'BFE.dev'> // 7
 type B = LengthOfString<''> // 0
 type C = LengthOfString<98> // 0

 export {}